Heat coming through dash/front firewall???

[NSX-Tuner]

Is it normal to feel some heat coming from the dash/front firewall area when heater is off? Even with A/C on, I can feel a slight amount of heat coming from the firewall area, around my legs and feet. With the high temps last weekend, it became even more noticeable. Also, I checked the A/C vent modes and have it set to flow air to the face only. Yes, I did a search but query result was empty.

 

[Acura NsX Pilot]

How high was the temp ?

I have never experienced this in mine and its a 91

 

[NSX-Tuner]

How high was the temp ?

I have never experienced this in mine and its a 91

Last Saturday on the way up to Yosemite it hit 112+ degrees. But I've always noticed a slight amount of heat even when it's not so hot. In fact, in mild weather, I have to drive with the windows down or run the A/C, otherwise it gets a bit stuffy and warm inside the passenger compartment.

I'm wondering if there's a heater vent stuck slightly open.

 

[topman2005]

i have similar problem as well, and i dunno why

 

[NSXCELERATE]

with an 05 I would take it straight to the dealer

 

[enesexdreamer]

i too sometimes feel a little heat under the dash.

 

[Joshs]

I never noticed it myself but my gf was driving us the other night and she noticed the same thing (more sensitive legs perhaps?)... I turned on the lower vent and that helped. Probably unrelated but my a/c is not functional at the moment.

-Josh

 

[Ruined 2]

I've noticed this in mine as well. It's usually only on warmer days. I never use the AC. I hate AC. Top out windows down unless it's pouring .

I've tried all kinds of mode selections on the climate control for air pass-through, but it doesn't seem to affect it. I just figured it was heat from the coolant passage tubes.

 

[GreggMarkarian]

I am frustrated by this too. Since day one with this car I noticed that there didn't seem to be any way to get cool outside air directly into the car through the vents. Its too loud going 70mph on the highway with the windows down, and I don't like using A/C unless its really neccessary. Why is it, with such an expensive car, it can be a beautiful 65° outside, but I have to run the A/C to get it down to 70° in the car? And don't say its because the engine's behind me and the radiator's up front. I owned plenty of MR2s before the NSX and if it was 65° out I could always get nice 65° air blowing on my feet and face without turning the A/C on.

The only difference with the MR2 was it didn't have any fancy automatic climate control. It seems like the NSX's system passes all air past the heater core no matter what, and then uses the A/C to cool it as needed. Like it was designed to be left on full auto all the time so the A/C could kick in whenever it needed to (and so this is what I have resorted to doing, and it works great). Maybe they figured people with enough money to buy this car would leave the A/C on all the time anyway.

I dunno. I could count on one hand the things that annoy me about the NSX, but this is one of them.
-Gregg

 

[Briank]

Greg

The air does go through the heater core but it has a valve that should shut off when no heat is needed. You may need an adjustment in the cable that operates the valve or you may have a CCU problem that has stopped disabled the control of the valve.

 

[GreggMarkarian]

You may need an adjustment in the cable that operates the valve or you may have a CCU problem that has stopped disabled the control of the valve.

Hey! Sounds promising! I'll have it checked out. Thanks!
-Gregg

 

[jagtiger]

Greg

The air does go through the heater core but it has a valve that should shut off when no heat is needed. You may need an adjustment in the cable that operates the valve or you may have a CCU problem that has stopped disabled the control of the valve.

Hi Brian, this is exactly my issue per my PMs to you. I already took the heater motor cable out for the heater valve but still have heat issue in the cabin. I just read your pm from the other day so I might just have to try and installing a working CCU from you and see if my current CCU is the problem.

Thanks

 

[shawn110975]

here another idea, there is a foam sticker that seals the blower to the firewall I have seen a bunch lately that the foam is completely gone so hot air from the radiator is being pushed into the cabin

take blower off and look at seal its prob not there anymore. its like the seal for the real tails kinda

 

[Briank]

Hi Brian, this is exactly my issue per my PMs to you. I already took the heater motor cable out for the heater valve but still have heat issue in the cabin. I just read your pm from the other day so I might just have to try and installing a working CCU from you and see if my current CCU is the problem.

Thanks

If the heater valve is closed the ccu is doing all it has control of so replacing it is not likely to provide any change is the problem.

 

[NSX2398]

With a black dash and a large, canted windshield, I just assumed that the dash was getting too much solar gain and that any air flowing through it would warm up even if it was slightly cool coming in from outside. Might have been my imagination but I thought that running the a/c for a while allowed the dash to cool down enough so that it wasn't warming the air any more .. but that might have been wishful thinking on my part and I don't think it would explain hot air coming in under the dash. I do know that if the car dash has been sitting directly in the sun, it takes a lot longer for the a/c to cool the car down .. but maybe I just need a refridgerant refill.

 

[Larry Bastanza]

As I read this my first thoughts were: Water Valve mis-adjusted(seen this many times) or CC board toasted!!

Greg

The air does go through the heater core but it has a valve that should shut off when no heat is needed. You may need an adjustment in the cable that operates the valve or you may have a CCU problem that has stopped disabled the control of the valve.

 

[Honcho]

As I read this my first thoughts were: Water Valve mis-adjusted(seen this many times) or CC board toasted!!

+1 I had this exact problem and a helpful member at NSXPO showed me how to adjust the water valve. Totally fixed it- no more hot air.

 

[Dr. JL]

The foam seals from the fan and/or heater-evaporator unit have disintegrated. I removed my h-e unit due to a weeping heater core from my '91. I noticed ALL the foam seals on both the h-e unit and fan module were disintegrated inside and out. Hot air from the radiator is making its way into the cabin. All the foam seals on the vents/HVAC tubes in by NSX have disintegrated also.

 

[davidf]

Wow, an 8 year old thread revived. FWIW, I did drive over a year with "not so cold" air coming from my AC vents. Prior to that I'd had my evap replaced and it was never quite cold since. Brian did save the day after I waited a year to inquire. Cable adjustment fixed me right up.

 

[bngl3rt]

+1 I had this exact problem and a helpful member at NSXPO showed me how to adjust the water valve. Totally fixed it- no more hot air.

Is there a good link or DIY for this? Would be nice to fix it.

 

[JW]

Is there a good link or DIY for this? Would be nice to fix it.

I did this with my car and it stays cool inside now. Step 15.



91 NSX Red/Black
09 VW Jetta TDI White